A large number of glass and glass-ceramic materials are known. The majority of oxide glass systems utilize well-known glass-formers such as SiO2, B2O3, P2O5, GeO2, TeO2, As2O3, and V2O5 to aid in the formation of the glass. Some of the glass compositions formed with these glass-formers can be heat-treated to form glass-ceramics. The upper use temperature of glasses and glass-ceramics formed from such glass formers is generally less than 1200° C., typically about 700–800° C. The glass-ceramics tend to be more temperature resistant than the glass from which they are formed.
In addition, many properties of known glasses and glass-ceramics are limited by the intrinsic properties of glass-formers. For example, for SiO2, B2O3, and P2O5-based glasses and glass-ceramics, the Young's modulus, hardness, and strength are relatively low. Such glass and glass-ceramics generally have inferior mechanical properties as compared, for example, to Al2O3 or ZrO2.
Some less or non-conventional glasses such as glasses based on rare earth oxide-aluminum oxide (see, e.g., U.S. Pat. No. 6,482,758 (Weber) and Japanese Document No. JP 2000-045129, published Feb. 15, 2000) are known, additional novel glasses and glass-ceramic, as well as use in new applications for both known and novel glasses and glass-ceramics, is desired.